The present invention relates to an electric rice cooker and, more particularly, to an electric rice cooker in which the cooking heater is controlled in accordance with the actual kettle temperature measured by a temperature sensor, thereby performing the rice cooking operation.
In a rice cooking machine, or rice cooker, designed to electrically heat the rice introduced, together with an appropriate amount of water, into a cooking kettle and perform its cooking operation on an automatic basis, measuring the actual temperature of the kettle with high precision during the cooking operation is important in performing the rice cooking operation effectively. The measured kettle temperature is utilized as the basis for effectively executing various cooking modes including what is called "twice cooking" which is known to those in the art. As a simple and easily understandable example, this kettle temperature data is used for suitably judging the time for deenergizing the cooking heater in order to complete the main cooking operation. That is, if the heater is deenergized when the actual kettle temperature has reached a goal temperature corresponding to the temperature at which the rice cooking is completed, it is possible to suitably control the duration for the succeeding rice cooking operation and also to reliably prevent scorching due to overheating.
Measuring the actual kettle temperature is generally carried out by an electric temperature sensor such as a thermistor. However, this type of temperature sensor is not reliable and is likely to cause conduction failure making it impossible for a cooking control circuit to effectively control the energization or deenergization of the heater. If the heater continues to heat when the temperature control is rendered ineffective, not only will the rice be scorched, but there will also be an increased risk of causing an electrical accident.